This invention relates to a terminal retainer connected to a connector housing of an electric connector, used for connection of wire harnesses or the like, to prevent a metal terminal, inserted in a terminal receiving chamber of the connector housing, from rearward withdrawal.
A common method of retaining a metal terminal received in a connector housing includes forming a flexible retaining arm integrally on an inner wall of a terminal receiving chamber, and causing the retaining arm to engage the metal terminal to be inserted into the terminal receiving chamber, thereby preventing rearward withdrawal of the metal terminal.
However, an adequate force for retaining the metal terminal cannot be obtained with the flexible retaining arm alone. Recently, an arrangement has been proposed in which a separate terminal retainer is used in combination with a connector housing to prevent more positively the withdrawal of the metal terminal. FIGS. 7 to show one such conventional retainer construction, disclosed in detail in Japanese Laid-open (Kokai) Patent Application No. 54678/89.
In this conventional construction, as shown in FIGS. 7A and 7B, a flexible retaining arm c engageable in a retaining hole g in a metal terminal f is provided at a terminal receiving chamber b of an insulative housing a. A through hole d communicating with the terminal receiving chamber b is formed in the outer peripheral wall of the insulative housing a, and a flexible lock portion e is formed on the edge of the through hole d. A double retainer member i is inserted into the through hole d and is engaged with the metal terminal f, thereby achieving a double retention function.
As shown in FIG. 8, the double retainer member i is made up of a plurality of plate-like bodies j integrally interconnected at their upper ends by a connecting plate k to provide a tooth-like configuration. Each plate-like body j has at its side retaining projections l which cooperate with retaining pieces h formed on the metal terminal f in an upstanding manner (FIG. 9). Complete lock pieces m are provided on the upper end portion (i.e., the connecting plate k) of the double retainer member i, and provisional lock pieces n are provided on the lower end portion (i.e., the lower ends of the plate-like bodies j).
FIG. 7A shows a provisionally-locked condition of the double retainer member i. Each provisional lock piece m of the plate-like body j inserted in the through hole d is engaged with a partition wall b of the terminal receiving chamber b, and each lock piece m is supported on the lock portion e of the insulative housing a, thus provisionally locking the double retainer member i. In this condition, since the retaining projections l are disposed outside of the terminal receiving chamber b, the insertion and removal of the metal terminal f can be made freely, and if the insertion is complete, the flexible retaining arm c is engaged in the retaining hole g to effect a primary retention function.
FIG. 7B shows a complete-locked condition of the double retainer member i. When this member i is depressed in a direction of an arrow in FIG. 7A, the lock portion e is flexed, so that each complete lock piece m is moved downwardly, thereby effecting complete locking. At the same time, the retaining projections l are moved into the receiving chamber to be disposed behind the retaining pieces h, and therefore the rearward withdrawal of the metal terminal f can be prevented in two different ways.
In the just-described conventional connector, since the double retainer member i can be provisionally locked relative to the insulative housing a, the two can be handled in a combined manner. This is convenient for transport and storage. However, the double retainer member can be changed from the provisionally-locked condition into the completely-locked condition in a single step, and therefore there is a possibility that the double retainer member inadvertently may be put into the completely-locked condition during transport or assembly of the connector, so that the metal terminal cannot be inserted. In this case, additional time is required to return the connector to its provisionally- locked condition.
Further, each body j of the double retainer member i is made of a thin plate, which does not have adequate strength. Therefore, there is another problem in that, when the double retainer member is inserted into the insulating housing, the bodies j may be flexed, so that the insertion operation cannot be carried out easily. Still further, the retaining projections l which cooperate with the retaining pieces h of the metal terminal f are provided on the side of the plate-like body, and therefore there is a further problem in that the retaining projections are small, thus failing to provide a sufficient retaining force.